[Leetcode]链表的中间结点

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */



struct ListNode* middleNode(struct ListNode* head)
{
    struct ListNode* slow,*fast;//定义快慢两个指针
    slow = fast = head;
    while(fast && fast->next)//考虑到结点个数的奇偶
    {
        slow = slow->next;
        fast= fast->next->next;
    }
    return slow;


}